I thought the standard Song3 had the bamboo midrange driver. These appear to be aluminum. Is this standard? What's the difference?

It was upgraded along the way .....

"Start with the RAAL 64-10 ribbon tweeter, add a 4" midrange with a bamboo an upgraded titanium cone and top things off with a 7.5" woofer that plays down to 33Hz with incredible power handling. The result is a combination that is sure to please"

I thought the standard Song3 had the bamboo midrange driver. These appear to be aluminum. Is this standard? What's the difference?

It is the exact same driver but with a titanium cone. Originally we went with bamboo due to lower cost. But when there were supply issues, we decided to upgrade to the titanium cone. It measures exactly the same as the bamboo and is a perfect drop-in replacement.